This invention relates generally to gas turbine engine turbines and more particularly to structural members of such engines.
Gas turbine engines frequently include a stationary turbine frame (also referred to as an inter-turbine frame or turbine center frame) which provides a structural load path from bearings which support the rotating shafts of the engine to an outer casing, which forms a backbone structure of the engine. The turbine frame crosses the combustion gas flowpath of the turbine and is thus exposed to high temperatures in operation.
It is known to provide a multi-piece, passively cooled turbine frame, with actively cooled turbine nozzle vanes positioned downstream therefrom. It is also known to provide a one-piece, passively cooled turbine frame which integrates a passively cooled turbine nozzle cascade.
From a thermodynamic standpoint it is desirable to increase operating temperatures within gas turbine engines as much as possible to increase both output and efficiency. However, as engine operating temperatures are increased, increased active cooling for turbine frame, turbine nozzle, and turbine blade components becomes necessary.
To address these cooling needs it is further known to provide a high-temperature capable multi-piece turbine frame incorporating actively cooled fairings and flowpath panels, and utilizing turbine nozzle vanes made from advanced ceramic materials that do not require cooling.
However, none of these turbine frame configurations integrate a one-piece turbine frame construction with conventional-configuration actively cooled nozzles.